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Annotation of prex-old/usr/lib/libc/gen/execvp.c, Revision 1.1.1.1

1.1       nbrk        1: /*-
                      2:  * Copyright (c) 1991, 1993
                      3:  *     The Regents of the University of California.  All rights reserved.
                      4:  *
                      5:  * Redistribution and use in source and binary forms, with or without
                      6:  * modification, are permitted provided that the following conditions
                      7:  * are met:
                      8:  * 1. Redistributions of source code must retain the above copyright
                      9:  *    notice, this list of conditions and the following disclaimer.
                     10:  * 2. Redistributions in binary form must reproduce the above copyright
                     11:  *    notice, this list of conditions and the following disclaimer in the
                     12:  *    documentation and/or other materials provided with the distribution.
                     13:  * 3. Neither the name of the University nor the names of its contributors
                     14:  *    may be used to endorse or promote products derived from this software
                     15:  *    without specific prior written permission.
                     16:  *
                     17:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     18:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     19:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     20:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     21:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     22:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     23:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     24:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     25:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     26:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     27:  * SUCH DAMAGE.
                     28:  */
                     29:
                     30: #include <sys/cdefs.h>
                     31: #include <assert.h>
                     32: #include <errno.h>
                     33: #include <stdio.h>
                     34: #include <stdlib.h>
                     35: #include <string.h>
                     36: #include <limits.h>
                     37: #include <paths.h>
                     38: #include <unistd.h>
                     39:
                     40: extern char **environ;
                     41:
                     42: int
                     43: execvp(const char *name, char * const *argv)
                     44: {
                     45:        const char **memp;
                     46:        int cnt;
                     47:        size_t lp, ln = 0;
                     48:        int eacces = 0;
                     49:        unsigned int etxtbsy = 0;
                     50:        char buf[PATH_MAX];
                     51:        const char *bp, *path, *p;
                     52:
                     53:        /* "" is not a valid filename; check this before traversing PATH. */
                     54:        if (name[0] == '\0') {
                     55:                errno = ENOENT;
                     56:                goto done;
                     57:        }
                     58:        /* If it's an absolute or relative path name, it's easy. */
                     59:        if (strchr(name, '/')) {
                     60:                bp = name;
                     61:                path = "";
                     62:                goto retry;
                     63:        }
                     64:        bp = buf;
                     65:
                     66:        /* Get the path we're searching. */
                     67:        if (!(path = getenv("PATH")))
                     68:                path = _PATH_DEFPATH;
                     69:
                     70:        ln = strlen(name);
                     71:        do {
                     72:                /* Find the end of this path element. */
                     73:                for (p = path; *path != 0 && *path != ':'; path++)
                     74:                        continue;
                     75:                /*
                     76:                 * It's a SHELL path -- double, leading and trailing colons
                     77:                 * mean the current directory.
                     78:                 */
                     79:                if (p == path) {
                     80:                        p = ".";
                     81:                        lp = 1;
                     82:                } else
                     83:                        lp = path - p;
                     84:
                     85:                /*
                     86:                 * If the path is too long complain.  This is a possible
                     87:                 * security issue; given a way to make the path too long
                     88:                 * the user may execute the wrong program.
                     89:                 */
                     90:                if (lp + ln + 2 > sizeof(buf))
                     91:                        continue;
                     92:                memcpy(buf, p, lp);
                     93:                buf[lp] = '/';
                     94:                memcpy(buf + lp + 1, name, ln);
                     95:                buf[lp + ln + 1] = '\0';
                     96:
                     97: retry:         (void)execve(bp, argv, environ);
                     98:                switch (errno) {
                     99:                case EACCES:
                    100:                        eacces = 1;
                    101:                        break;
                    102:                case ENOTDIR:
                    103:                case ENOENT:
                    104:                        break;
                    105:                case ENOEXEC:
                    106:                        for (cnt = 0; argv[cnt] != NULL; ++cnt)
                    107:                                continue;
                    108:                        if ((memp = alloca((cnt + 2) * sizeof(*memp))) == NULL)
                    109:                                goto done;
                    110:                        memp[0] = _PATH_BSHELL;
                    111:                        memp[1] = bp;
                    112:                        (void)memcpy(&memp[2], &argv[1], cnt * sizeof(*memp));
                    113:                        (void)execve(_PATH_BSHELL, (char * const *)memp,
                    114:                            environ);
                    115:                        goto done;
                    116:                case ETXTBSY:
                    117:                        if (etxtbsy < 3)
                    118:                                (void)sleep(++etxtbsy);
                    119:                        goto retry;
                    120:                default:
                    121:                        goto done;
                    122:                }
                    123:        } while (*path++ == ':');       /* Otherwise, *path was NUL */
                    124:        if (eacces)
                    125:                errno = EACCES;
                    126:        else if (!errno)
                    127:                errno = ENOENT;
                    128: done:
                    129:        return (-1);
                    130: }